Differential resonator.



E. H. MURPEE.

DIFFERENTIAL RESONATOR.

APPLICATION FILED DEO.29,1911.

vwawl oz Edward Patented Nov. 12, 1912.

- Wane/ooze EDWARD H. MURFEE, OF GAINESVILLE, GEORGIA.

DIFFERENTIAL RESONATOR.

Specification of Letters Patent.

Patented Nov. 12, 1912.

Application filed December 29, 1911. Serial No. 668.467.

To all whom it may concern:

Be it known that I, EDWARD H. MUREEE, a citizen of the United States, residing at Gainesville, in the county of Hall, State of Georgia, have invented certain new and-useful Improvements in Differential Resonators; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled-in the art to which it appertains to make and use the same.

This invention relates to resonators and has for an object to provide a device of this character that may be adjusted to resonance.

Most resonators of ordinary construction respond to but a single tone and therefore the principal object of the present invention is to provide a resonator which may be easily and quickly adjusted to respond to any tone for which it is adjusted. This adjustment of the device to resonance is effected through the instrumentality of a movable piston within a tube which is open atone end, .the piston forming an adjustable bottom for the tube, and furthermore having a hollow stem or piston rod which forms means for manipulating the piston and for leading the sound therefrom to the ear.

With the above objects in view the invention consists of certain novel details of construction and combination of parts hereinafter fully described and claimed, it being.

understood that various modifications may be made in the minor details of construction within the scope of the appended claims.

In the accompanying drawing forming part of this specification :Figure 1 is a side elevation of the resonator. Fig-. 2 is a longitudinal'sectional view through the resonator. F ig. 3 is a cross sectional view taken on the line 33 Fig. 2.

Referring now to the drawing in which like characters of reference designate similar parts, 10 designates a tube which is closed at one end by a plug 11. The tube may be formed of metal, glass, or other suitable material, in the present instance it is illustrated as being formed of glass, and arranged upon the outer face of the tube is a scale 12, the division lines of which denote centimeters and fractional parts thereof, although the division lines may be arranged to denote inches or fractional parts thereof within the scope of this invention.

Within the tube 10 is arranged a piston 13 which is provided with a hollow piston rod 14 the same being slidably fitted in an orifice 15 formed in the plug 11 and terminating in a conical nozzle 16 upon which is secured'curved stops 17 which bear against the ear and, limitmovement of the nozzle thereinto. A stub shaft 18 is engaged through one side of the tube 10 and is equipped at the inner end with a gear wheel 19 which meshes with rack teeth 20 formed on the piston rod, the outer end of the shaftbeing equipped with a hand wheel 21 by means of which the shaft may be rotated and the piston advanced or retracted within the tube 10.

It is to be understood that I am not limited to the above described means of manipulating the piston, but any preferred means may be employed, it being simply necessary that the piston be movably mounted in the tube to attain the end sought by this invention. Furthermore, I do not intend to limit the position of the scale as shown in the accompanying drawing, but may dispose the scale upon the piston rod itself in the event of the tube 10 being made of non-transparent material, and may resort to other changes within the scope of the attached claims.

The operation of the device is as follows: Suppose the overtone of a fundamental tone havinga known wave length is desired. The piston isbrought into registration with the division line of the scale on the tube which will presenta column of air in advance of the piston of a predetermined length. The length of this column of air will be a certain proportional part of the known length of the fundamental tone wave. Now when the fundamental is struck on any musical instrument, the tube and said column of, air will vibrate and give the tone for which the instrument is adjusted.

What is claimed, is

1. A resonator including a tube open at one end, a movable piston forming an adjustable closure in the tube, and a hollow stem opening through the piston and forming means for manipulating the piston'and for conducting sound to the ear.

2. A resonator including a tube open at one end, a movable piston forming a closure in the tube, a scale denoting the position of the piston within the tube, and a hollow stem carried by said piston in communication with the column of air in said tube in advance of said piston, said stem forming means for leading sound from in advance of said piston to the ear. I

3. A, resonator including a tube open at one end, a movable piston Within the tube forming an adjustable bottom in the tube, a hollow stem opening through the advance face of said piston and conducting sound from in advance of said piston to the ear, and means for manipulating-said piston.

4. A resonator including a tube open at one end, a movable piston forming a closure in the tube, a hollow piston rod engaged through said piston and having one end in communication With the column of air in said tube in advance of said piston, and having the opposite end equipped with ear en gaging means, said stem serving to lead sound from in advance of said piston to the ear, a scale for determining the position of said piston in said tube, and means for manipulating said piston.

In testimony whereof, I afliX my signature, in presence of two Witnesses.

EDWARD H. MURFEE. Witnesses:

FRANCIS BOYLE, JNO. T. MEANY. 

